Question

Which of the following is a factor of 9x2 + 21x + 10?

3x + 5
9x + 2
9x + 5
None of the Above

Answer 1

1, 90
2, 45
3, 30
6, 15
6/9, 15/9, 2/3, 5/3

3x+2, 3x+5

So, The Answer Is A

Answer 2

Answer: The correct option is (A) 3x + 5.

Step-by-step explanation: We are given to select the correct factor of the following quadratic expression :

`E=9x^2+21x+10`

To factorize the given expression, we must find two numbers whose sum is 21 and product is 90.

The factorization of the given expression is as follows :

`E\\\\=9x^2+21x+10\\\\=9x^2+15x+6x+10\\\\=3x(3x+5)+2(3x+5)\\\\=(3x+2)(3x+5).`

Therefore, the required factors of the given expression are (3x + 2) and (3x + 5).

Thus, the factor (3x + 5) is the correct one.

Hence, option (A) is CORRECT.